Close

Heat Sink Fabrication

A project log for LED Microscope Illuminator

An LED illuminator for an assembly microscope.

bharbourBharbour 04/19/2018 at 02:360 Comments

I spent the day machining some heat sinks. It did not go well, but in the end, I have 3 usable heat sinks. The mounting holes in the LED PCBs are undersized. They were spec'd at 0.93" which should have been a clearance hole for a 3-48 machine screw, but they needed to be spec'd to the next size up. I tried to drill and tap a heat sink for a 2-56 machine screw, but the drill bit snapped in the hole. Thinking I got lucky because there was enough bit sticking out of the hole, I extracted a piece. It turned out the bit snapped in multiple places, and the deeper pieces were un-removable. Considering that there was a couple of hours of work in the part by that time, I rotated the PCB and drilled new holes for the 3-48 screws. All told, the dimensions don't match the drawings, but stuff fits and should work. Now I need to wait for more bare PCBs to come in.


Assembled the first complete light head and it went together correctly and looks good. Initial tests were done using the 4000K version of the LED and the board that I put together today uses the 3000K version. It looks very much like the light from an incandescent bulb, which is what I want.

Discussions